The present invention relates to improvements in closure devices for plastic storage bags, and more particularly, to plastic reclosable fasteners with sliders for opening and closing the reclosable fasteners on the bag and end stops with engagement means for releasably latching the sliders at the closing end of the bags.
The use of closure devices for fastening storage containers, including plastic bags, is generally known. Furthermore, the manufacture of closure devices made of plastic materials is generally known to those skilled the in the art, as demonstrated by the numerous patents in this area.
A particularly well-known use for closure devices is in connection with flexible storage containers, such as plastic bags. In some instances, the closure device and the associated container are formed from thermoplastic materials, and the closure device and the sidewalls of the container are integrally formed by extrusion as a single piece.
Alternatively, the closure device and sidewall of the container may be formed as separate pieces and then connected by heat sealing or any other suitable connecting process. In either event, such closure devices are particularly useful in providing closure means for retaining matter within the bag.
Conventional closure devices typically utilize mating fastening strips or closure elements, which are used to selectively seal the bag. In addition, sliders may be provided for use in opening and closing the fastening strips. Such reclosable bags equipped with sliders are known in the art as xe2x80x9cslider bags.xe2x80x9d The slider may include a separator which extends at least partially between the fastening strips. When the slider is moved in the opening direction, the separator divides or deoccludes the fastening strips and opens the bag. When the slider is moved in the closing direction, the slider closes or occludes the fastening strips.
It is well known in the art to provide one or both ends of the reclosable fastener of a slider bag with an end stop to prevent movement of the slider past the ends of the bag. The end stop may be formed from the material of the fastening strips as is known from U.S. Pat. No. 5,950,285 to Porchia et al. Alternatively, the end stop may be formed as a separate plastic clip that is fused with the ends of the fastening strips during manufacture of the bag in accordance with the teachings of U.S. Pat. No. 5,448,807 to Herrington. The end stop may also consist of a separate u-shaped plastic clip that straddles the reclosable fastener and wherein individual clamping members of the clip are secured together by a plastic rivet that pierces the film material of the bag below the reclosable fastener.
It is desirable to be able to latch or secure the slider in its closed position to prevent the bag from accidentally opening. U.S. Pat. No. 5,301,395 to Richardson et al. discloses an end stop provided with an upward pointing hook member at its bottom forward facing edge. The hook member is adapted to extend into a cooperating recess on the bottom wing of the slider. As stated in the disclosure of this patent, the engagement of the recess by the hook member provides the user with a feel of a definite parking position for the slider when the bag is closed. To open the bag, the user must first disengage the hook member from the recess. This opening procedure requires use of brute force to separate the engaged elements. Repeated uses of the slider may cause the inter-engaging parts to wear or weaken and thus diminish the effectiveness of the positive latching feel of the closure.
It would be desirable to releasably latch a slider to an end stop on a bag provided with a reclosable fastener without having to use brute force in order to separate the slider from latching engagement with the end stop.
The present invention provides a closure device for a slider bag with a slider and an end stop having quick release latching means operable to releasably latch the slider in the closed position and release the slider with minimal user applied force. The closure device comprises first and second interlocking fastening strips arranged to be interlocked over a predetermined length. The slider is slidably disposed on the interlocking fastening strips for facilitating the occlusion and deocclusion of the fastening strips when moved towards first and second ends of the fastening strips. The first and second ends of the fastening strips are secured together and an end stop is provided to the first, closing end of the fastening strips. The end stop is provided with quick release latching structure engagable with cooperating latch-receiving structure provided to the mating or opening end of the slider to secure the slider when it is moved into engagement with the end stop at the closing end of the bag.
In accordance with a preferred embodiment of the invention, the slider is configured as an inverted u-shaped member having an upper portion disposed above the fastening strips and a pair of downwardly extending side walls disposed adjacent to the respective first and second fastening strips of the fastener. The quick release latching structure of the end stop includes a pair of tangs or latch members, disposed spaced apart and adjacent to the first and second fastening strips. Each latch member extends lengthwise away from the closing end of the bag and towards the opening end of the slider and has an outward extending ridge member or projection adapted to be receivingly engaged by a corresponding recess provided to the respective inside side wall surfaces of the opening end of the slider. The tangs or latch members are bendable or deflectable at their free ends, much like a diving board, and are designed to be xe2x80x9cgrandmother friendlyxe2x80x9d so that they require only a moderate inward pinching force by a user""s thumb and finger to release engagement of the slider.
In accordance with an alternate embodiment of the invention, the quick release latching means comprise a single latch member disposed along one sidewall of the end stop. The procedure for unlatching the slider is essentially the same as above whereby the user applies inward pressure to one side of the end stop to initiate disengagement with the slider.
In accordance with another alternate embodiment of the invention, the quick release latching means comprise a single latch member disposed along the top portion of the end stop. The single top-mounted latch member includes an upstanding ridge member or projection adapted to engage a corresponding recess provided to inner wall of the slider top portion. To initiate unlatching of the slider from the end stop, the user pushes downwardly on the top-mounted latch member of the end stop to move the ridge member or projection out of engagement with the recess in the slider while moving the slider in the opening direction.
In accordance with yet another alternate embodiment of the invention, the engagement and receiving structural parts are reversed whereby the end stop is provided with one ore more recesses and the slider is provided with one or more latch members, each having a ridge or projection adapted to be receivingly engaged within the corresponding recess in the end stop.
Methods and apparatus which incorporate the features described above and which are effective to function as described above constitute further, specific objects of the invention. Other objects and advantages of the invention will become apparent upon reading the following description and upon reference to the drawings.